1. Field
Embodiments described herein relate to a nonvolatile semiconductor memory device.
2. Description of the Related Art
A memory cell configuring a nonvolatile semiconductor memory device such as a NAND type flash memory or a NOR type flash memory includes a control gate and a charge accumulation layer. The memory cell changes its threshold voltage based on a charge accumulated in the charge accumulation layer, and stores a magnitude of this threshold voltage as data. In recent years, raising of density of the memory cells in such nonvolatile semiconductor memory devices has been proceeding.